Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/48—Tyre cords
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/02—Carcasses
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
  • D07B1/0626—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration the reinforcing cords consisting of three core wires or filaments and at least one layer of outer wires or filaments, i.e. a 3+N configuration
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
  • D07B1/0633—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration having a multiple-layer configuration
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2023—Strands with core
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2024—Strands twisted
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2024—Strands twisted
  • D07B2201/2029—Open winding
  • D07B2201/203—Cylinder winding, i.e. S/Z or Z/S
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2024—Strands twisted
  • D07B2201/2029—Open winding
  • D07B2201/2031—Different twist pitch
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2024—Strands twisted
  • D07B2201/2029—Open winding
  • D07B2201/2031—Different twist pitch
  • D07B2201/2032—Different twist pitch compared with the core
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2038—Strands characterised by the number of wires or filaments
  • D07B2201/2039—Strands characterised by the number of wires or filaments three to eight wires or filaments respectively forming a single layer
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2038—Strands characterised by the number of wires or filaments
  • D07B2201/204—Strands characterised by the number of wires or filaments nine or more wires or filaments respectively forming multiple layers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2047—Cores
  • D07B2201/2052—Cores characterised by their structure
  • D07B2201/2059—Cores characterised by their structure comprising wires
  • D07B2201/2061—Cores characterised by their structure comprising wires resulting in a twisted structure
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2083—Jackets or coverings
  • D07B2201/2089—Jackets or coverings comprising wrapped structures
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2095—Auxiliary components, e.g. electric conductors or light guides
  • D07B2201/2097—Binding wires
  • D07B2201/2098—Binding wires characterized by special properties or the arrangements of the binding wire
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2501/00—Application field
  • D07B2501/20—Application field related to ropes or cables
  • D07B2501/2046—Tire cords
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S57/00—Textiles: spinning, twisting, and twining
  • Y10S57/902—Reinforcing or tire cords
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T152/00—Resilient tires and wheels
  • Y10T152/10—Tires, resilient
  • Y10T152/10495—Pneumatic tire or inner tube
  • Y10T152/10855—Characterized by the carcass, carcass material, or physical arrangement of the carcass materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2915—Rod, strand, filament or fiber including textile, cloth or fabric
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2936—Wound or wrapped core or coating [i.e., spiral or helical]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]

Definitions

• the present invention relates to a wire rope that can be used to reinforce a carcass reinforcement of a tire, such as a heavy-weight tire, a composite fabric that can be used as a ply of such a carcass reinforcement, a carcass reinforcement comprising this fabric, and a tire incorporating this carcass reinforcement.
• hoop wire of reduced diameter usually between 0.10 mm and 0.25 mm
• this hoop wire is wound at a very small pitch (for example ranging from 3 mm to 5.5 mm) and in a direction opposite or identical to that of the winding of the son of said outer layer.
• the French patent document FR-A-1 011 211 discloses a shrouded wire rope for a tire intended to have a satisfactory resistance to buckling forces in normal rolling.
• This cable is provided with a hoop of natural or artificial textile material which consists of a thread or a ribbon.
• French patent document FR-A-2 551 104 discloses a shrink-wrapped wire rope for reducing the fretting wear of the hoop.
• This cable is multilayer type, and the band used is formed of a flattened section wire plastic or rubber, or composite metal / plastic or metal / rubber.
• DE-A-4 120 554 discloses a wire rope with a non-metallic ferrule which shrinks hot to reduce corrosion and wear by contact between the ferrule and the outer layer of the wire.
• This hoop can be formed of a polyamide or a polyester.
• South Korean KR-B-95/04085 discloses a steel cable having a non-metallic ferrule which is formed of one or more cables.
• This hoop can be chosen from a family of textile or non-textile polymers comprising nylon®, polyethylene, polyurethane, rayon, fiberglass, carbon fiber and an aromatic naming polyamide. Kevlar®.
• EP-A-566 392 discloses a pneumatic wire rope, which is provided with a flattened section wire, in order to reduce the thickness of the cable and the reinforcement ply incorporating it, all giving it improved mechanical properties.
• This wire may be both metallic wire made of plastic, for example aramid or nylon®, or composite metal / plastic.
• a disadvantage of these cables provided with a textile hoop resides in the relatively reduced "flat" rolling endurance they confer on a tire, such as a heavy-vehicle tire, whose carcass reinforcement is provided with it. , in particular in comparison with the endurance obtained with cables provided with a metal band.
• thermotropic aromatic polyester-amide polyester-textile fret makes it possible to increase a very significant way the mileage traveled in "flat" driving by a tire incorporating a wire rope which comprises said hoop as reinforcement element of its carcass reinforcement, compared to the mileage obtained under the same conditions using a hoop of identical geometry which consists of a metal or other textile, such as aramid, conferring on this cable according to the invention an improved mechanical resistance with respect to compression forces and strong flexures including the reinforcement of carcass is the seat in these conditions of running "flat", without penalizing the resistance of this cable according to the invention vis-à-vis fretting wear by compared to that presented by cables provided with an aramid fret.
• wire rope will be understood to mean a cable of which at least the outer surface on which said hoop is wound is of a metallic nature (ie whose external surface consists of wires or assemblies of metal wires. ).
• the fretted cable according to the invention is used as reinforcing element of a carcass reinforcement of a heavy-vehicle tire.
• the starting polymer which is used to obtain the hoop according to the invention is any thermotropic aromatic polyester or polyester amide (ie in molten crystal-liquid form), which is spinnable in this molten state.
• thermotropic nature of a polymer is determined by optical measurement, by testing the optical anisotropy of this polymer by observation in the melt phase (ie above the melting point of the polymer) of a drop of said polymer between a polarizer and a linear analyzer crossed a polarization optical microscope, at rest, that is to say in the absence of dynamic stress.
• thermotropic polyesters or polyesteramides are said to be “wholly aromatic" and have been described in a large number of documents.
• thermotropic aromatic polyester which consists essentially of 6-oxy-2-naphthoyl and (B) 4-oxybenzoyl repeat units (A), the A / B molar ratio being in a range from from 10:90 to 90:10, preferably from 20:80 to 30:70.
• thermotropic aromatic polyester is marketed in particular by the company Hoechst Celanese under the name "VECTRA" with a molar ratio A: B equal to 27:73, and it has been described in the patent document US-A-4 161 470.
• Monofilament means a unit filament whose diameter or thickness D (ie the smallest transverse dimension of its cross-section when it is not circular) is at least equal to 40 ⁇ m (minimum titre 1.7 tex).
• This definition thus covers both monofilaments of substantially cylindrical shape (i.e. circular section) or oblong monofilaments, of flattened shape, or strips or films of thickness D.
• said hoop wire consists of a monofilament.
• this monofilament has the characteristic of not shrinking when hot, which is expressed by the relation ⁇ L ⁇ 0, where ⁇ L represents its variation in length (in%) after 2 minutes at 235 ⁇ 5 ° C under a pretension of 0.2 cN / tex.
• ⁇ L represents its variation in length (in%) after 2 minutes at 235 ⁇ 5 ° C under a pretension of 0.2 cN / tex.
• WO-A-98 / 55,674 for the conditions for measuring this thermal variation in length. All the mechanical properties hereafter are measured on monofilaments that have been subjected to prior conditioning. ie storage (after drying) for at least 24 hours, before measurement, in a standard atmosphere according to the European standard DIN EN 20139 (temperature of 20 ° C ⁇ 2 ° C and hygrometry of 65% ⁇ 2%) .
• the title of the monofilaments is determined on at least three samples, each corresponding to a length of 50 m, by weighing this length of monofilament. The title is given in tex (weight in g of 1000 m of monofilament - reminder: 0.111 tex equal to 1 denier).
• the mechanical properties in extension are measured in a known manner using a traction machine "ZWICK GmbH & Co" (Germany) type 1435 or 1445.
• the monofilaments are subjected to traction on an initial length of 400 mm at a nominal speed of 50 mm / min. All the results given in the remainder of the present description are an average of 10 measurements.
• the initial modulus is defined as the slope of the linear part of the force-elongation curve, which occurs just after a standard pretension of 0.5 cN / tex.
• the elongation at break is indicated in percentage.
• the parameter D which then represents the smallest dimension of the monofilament in a plane normal to the axis of the latter, is no longer determined by calculation but experimentally, by optical microscopy on a cross section of this monofilament, the latter being for example previously coated in a resin to facilitate cutting.
• the band used in a cable according to the invention preferably has a diameter or a thickness ranging from 0.08 mm to 0.40 mm.
• this band has a toughness greater than 180 cN / tex, an initial modulus greater than 3500 cN / tex, and an elongation at break greater than 2.5%.
• the cable ferrule according to the invention is wound helically on said outer surface in a pitch ranging from 3 mm to 5.5 mm.
• the hoop according to the invention is subjected to a sizing treatment, in order to allow its adhesion to the rubber composition intended to be secured to the cables which are each provided with this hoop.
• said cable is of the multilayer type.
• such a multi-layer cable can meet for example the formula (L + M) or (L + M + N), being formed of a core of L wire (s) surrounded by at least one layer of M son which is itself optionally surrounded by an outer layer of N son, with in general L varying from 1 to 4, M varying from 3 to 12, N varying from 8 to 20.
• these multilayer cables respond to one or the other of said formulas (L + M) or (L + M + N) with L greater than 1, and they then comprise a core consisting of several son assembled parallel (ie in an infinite step) or coiled together in a helix in a finite step.
• the cables according to the invention can be not only multilayer cables, but also all strand-type at least partially metallic cables (assembled by the also known stranding technique).
• a composite fabric according to the invention comprises a rubber composition which is reinforced by the fretted cables according to the invention, and this fabric can be used as a carcass reinforcement ply of a tire, advantageously a heavy-weight tire.
• die elastomer is used herein to mean a diene elastomer derived at least in part from conjugated diene monomers having a level of units or units of diene origin (conjugated dienes) which is greater than 15% (%). in moles).
• conjugated diene monomers having a level of units or units of diene origin (conjugated dienes) which is greater than 15% (%). in moles).
• diene elastomers such as butyl rubbers or copolymers of dienes and alpha-olefins such as EPDM do not enter the definition above and may be particularly described as "essentially saturated" diene elastomers (low or very low diene origin, always less than 15%).
• the term “highly unsaturated” diene elastomer is particularly understood to mean a diene elastomer having a content of units of diene origin (conjugated dienes) which is greater than 50%.
• the diene elastomer of the composite according to the invention is preferably chosen from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, the various butadiene copolymers, the various isoprene copolymers, and mixtures of these elastomers.
• Particularly suitable polybutadienes are those having a 1,2-unit content of between 4% and 80% or those having a cis-1,4 content of greater than 80%.
• synthetic polyisoprenes cis-1,4-polyisoprenes are particularly suitable, preferably those having a cis-1,4 bond ratio greater than 90%.
• copolymers of butadiene or isoprene is meant in particular the copolymers obtained by copolymerization of at least one of these two monomers with one or more vinyl-aromatic compounds having from 8 to 20 carbon atoms.
• Suitable vinyl aromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the commercial "vinyl-toluene" mixture, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, vinylmesitylene and divinylbenzene. vinyl naphthalene.
• the copolymers may contain between 99% and 20% by weight of diene units and between 1% and 80% by weight of vinyl aromatic units.
• butadiene or isoprene copolymers mention will preferably be made of butadiene-styrene copolymers, isoprene-butadiene copolymers, isoprene-styrene copolymers or isoprene-butadiene-styrene copolymers.
• a diene elastomer chosen from the group of highly unsaturated diene elastomers consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR) and butadiene-styrene copolymers (SBR) is preferably used.
• BR polybutadienes
• NR natural rubber
• IR synthetic polyisoprenes
• SBR butadiene-styrene copolymers
• BIR isoprene-butadiene copolymers
• SIR isoprene-styrene copolymers
• SBIR butadiene-styrene-isoprene copolymers
• the rubber composition of the invention is a diene elastomer of natural rubber or synthetic polyisoprene.
• blends (blends) of these polyisoprenes with other highly unsaturated diene elastomers in particular with SBR or BR elastomers as mentioned above.
• the rubber matrices of the composites of the invention may contain one or more elastomer (s) diene (s), which (s) last (s) can be used (s) in combination with any type of elastomer synthetic other than diene, or with polymers other than elastomers, for example thermoplastic polymers.
• elastomer (s) diene (s) which (s) last (s) can be used (s) in combination with any type of elastomer synthetic other than diene, or with polymers other than elastomers, for example thermoplastic polymers.
• the rubber compositions of the composite fabrics according to the invention also comprise all or part of the additives normally used in the manufacture of tires, such as reinforcing fillers such as carbon black or silica, anti-aging agents, for example antioxidants, extension oils, plasticizers or agents facilitating the use of the compositions in the green state, a crosslinking system based on either sulfur, or sulfur and / or peroxide donors, accelerators, activators or vulcanization retarders, acceptors and donors of methylene, resins, known adhesion promoter systems of the "RFS" type (resorcinol-formaldehyde-silica) or metal salts, especially cobalt salts.
• additives normally used in the manufacture of tires such as reinforcing fillers such as carbon black or silica, anti-aging agents, for example antioxidants, extension oils, plasticizers or agents facilitating the use of the compositions in the green state, a crosslinking system based on either sulfur, or sulfur and / or peroxide donors, accelerators,
• the composite fabric according to the invention can be in various forms, for example in the form of a sheet, a strip, a strip or a rubber block in which the metal reinforcement is incorporated by means of various means known to those skilled in the art, such as, for example, molding, calendering or extrusion means.
• the composite fabric according to the invention gives a heavy-weight tire particularly improved endurance in rolling "flat”.
• a carcass reinforcement of a tire according to the invention such as a heavy-weight tire, comprises this composite fabric, and a tire according to the invention comprises this carcass reinforcement.
• corrugated traction test is a fatigue test well known to those skilled in the art, in which the test material is fatigued in pure uniaxial extension (extension-extension), that is to say without any stress of compression.
• the principle is the following.
• a sample of the cable to be tested, held at each of its two ends by the two jaws of a traction machine, is subjected to a tensile stress or extension whose intensity ⁇ varies cyclically and symmetrically ( ⁇ moy ⁇ ⁇ a ) around an average value ( ⁇ moy ), between two extreme values ⁇ min ( ⁇ moy - ⁇ a ) and ⁇ max ( ⁇ moy + ⁇ a ) framing this mean value, under a load ratio "R" ( ⁇ min / ⁇ max ) determined.
• test is conducted as follows.
• a first amplitude of stress ⁇ a is chosen (generally in a range of about 1/4 to 1/3 of the resistance Rm of the cable) and the fatigue test is started for a maximum of 10 5 cycles (frequency 30 Hz), the charge ratio R being chosen equal to 0.1.
• a new amplitude ⁇ a (lower or higher than the previous one, respectively) is applied to a new test piece, by varying this value ⁇ a according to the so-called "staircase” method (Dixon & Mood, Journal of the American statistical association, 43, 1948, 109-126).
• the "belt” test is a known fatigue test which has been described for example in applications EP-A-648 891 or WO-A-98/41682, the test steel cables being incorporated into a rubber article which it is vulcanized.
• the principle of this test is as follows.
• This belt is then subjected to the following stresses.
• the belt is rotated around two rollers, so that each elementary portion of each cable is subjected to a tension of 12% of the initial breaking force and undergo cycles of variation of curvature which make it pass from a radius Infinite curvature with a radius of curvature of 40 mm (pulley diameter of 80 mm), and this for 50 million cycles.
• the test is carried out under a controlled atmosphere, the temperature and humidity of the air in contact with the belt being maintained at about 20 ° C and 60% relative humidity.
• the duration of the stresses for each belt is of the order of 3 weeks.
• the cables are extracted from the belts by peeling, and the residual breaking force of the tired cable wires is measured.
• the fatigue force deceleration after fatigue (denoted ⁇ Fm and expressed in%) is calculated by comparing the residual breaking force with the initial breaking force.
• the decay in breaking strength thus obtained reflects the level of fretting wear of the cable tested.
• the criterion for stopping these tests is the bursting of the tire, following a substantial deterioration of the cables of its carcass reinforcement.
• These cables are differentiated from each other only by the nature of the material of the band which they are provided and by the number of elementary filament (s) constituting said hoop.
• a first fretted cable "control” is characterized by a metal band formed of a pearlitic steel wire 0.15 mm in diameter.
• a second "control" cord is characterized by a multifilamentary textile yarn formed of a neighboring yarn of 22 tex, which consists of 100 elementary filaments of aramid Kevlar® denomination, each elementary filament having a diameter of about 12 ⁇ m. These elementary filaments are "overstretched” (i.e. twisted together) by a coefficient Z100 (twist of 100 revolutions / meter in the Z direction) and they are glued in a known manner.
• a third "witness" shrunk cable differs only from the preceding one in that said elementary filaments are "overstretched” according to a coefficient Z300 (twist of 300 revolutions / meter in the Z direction).
• a hoop cable according to the invention is characterized by a textile hoop formed of a single monofilament of about 25 tex (this monofilament having a diameter of 0.15 mm) which is made of a thermotropic aromatic polyester.
• This polyester is marketed by HOECHST CELANESE under the name "VECTRA”.
• This monofilament has been bonded in the same manner as for the aramid hoop of said second and third "control" cables.
• Table 1 below shows the mechanical properties of the hoop wire used for each "witness" shrunk cable and according to the invention.
• the dynamometric measurements such as the breaking force Fm (maximum load in N), the elongation at break At (total elongation in%) or the initial modulus (cN / tex) are made in tension according to the ISO 6892 standard of 1984.
• thermotropic aromatic polyester hoop according to the invention has a toughness which is very much greater than the toughness of a steel or aramid hoop.
• Table 2 shows the properties of the "control" cables and according to the invention which were respectively obtained by means of the hoop wires detailed in Table 1.
• Table 2 ⁇ / u>: Linear mass (g / m) No internal layer twisting (mm) No twisting outer layer (mm) No fret assembly (mm) Strength at break Fm (N) Elongation at break At (%) First "witness” cable 2,293 6.26 12.5 3.5 780.5 1.88 Second “witness” cable 2,275 6.17 12.82 3.5 812.5 2.49 Third “witness” cable 2,295 6.3 13,05 3.5 808.7 2.47 Invention cable 2,292 6.15 12.62 3.5 802.2 2.48
• the tensile strength Fm and elongation at break At for the fretted cables were made in tension according to ISO 6892 of 1984.
• thermotropic aromatic polyester hoop gives the cable according to the invention a force and an elongation at break which are greater than those obtained with a steel hoop (first "control” cable), which is due to less contact pressure when tensioning the cable. It can be deduced from an improvement in the tensile strength and fatigue performance of the cable according to the invention, with respect to this first "control" cable.
• This table 2 also shows that this hoop according to the invention gives the cable which incorporates a force and an elongation at break which are substantially similar to those obtained with an aramid hoop (second and third cables "control").
• a first endurance test consisted in measuring the endurance limit ⁇ D (MPa) in corrugated traction of each of the aforementioned cables.
• a second endurance test consisted in measuring the fretting wear (in%) of each of these cables, using a "belt” test. More precisely, we have measured for each cable the degradation in wear of each wire of the inner layer, each wire of the outer layer, and all the son of the cable.
• a third endurance test consisted in measuring the mileage traveled in "flat” driving by “control” heavy-weight tires and according to the invention respectively comprising “witness” shrouded cables and according to the invention in their armatures. carcass.
• a reference base 100 has been attributed to the mileage traveled by a first "control” tire comprising said first “control” cables (whose hoop is made of steel), results identified as greater than 100 testifying to a mileage obtained while driving ""flat” which exceeds that of this first tire “control”, and conversely for results identified as being less than 100.
• Table 3 below presents the results obtained for each endurance test.
• thermotropic aromatic polyester hoop gives the cable according to the invention a fatigue endurance which is greater than that obtained with a steel hoop (endurance limit in undulated corrugated traction of more than 40 MPa). or even in aramid (endurance limit in corrugated traction increased by nearly 10 MPa).
• thermotropic aromatic polyester hoop gives the cable according to the invention a fretting wear resistance of the wires of the cable, which is substantially improved with respect to that obtained with a steel hoop, and which is practically similar to that obtained with an aramid fret.

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• 2001
  • 2001-12-07 FR FR0115889A patent/FR2833277A1/fr active Pending
• 2002
  • 2002-12-04 WO PCT/EP2002/013708 patent/WO2003048447A1/fr active IP Right Grant
  • 2002-12-04 AT AT02792886T patent/ATE337430T1/de not_active IP Right Cessation
  • 2002-12-04 JP JP2003549621A patent/JP4326952B2/ja not_active Expired - Fee Related
  • 2002-12-04 CN CNB028243862A patent/CN100427674C/zh not_active Expired - Fee Related
  • 2002-12-04 AU AU2002358601A patent/AU2002358601A1/en not_active Abandoned
  • 2002-12-04 DE DE60214241T patent/DE60214241T2/de not_active Expired - Lifetime
  • 2002-12-04 EP EP02792886A patent/EP1466048B1/fr not_active Expired - Lifetime
• 2004
  • 2004-05-21 US US10/850,862 patent/US7380579B2/en not_active Expired - Fee Related

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